Htn

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Htn

  1. 1. HypertensionHypertensionDefinition:Definition: the force exerted by the bloodthe force exerted by the bloodagainst the walls of the bleed vesselsagainst the walls of the bleed vesselsAdequate to maintain tissue perfusion duringAdequate to maintain tissue perfusion duringactivity and restactivity and restArterial blood pressure: primary function ofArterial blood pressure: primary function ofcardiac output and systemic vascular resistancecardiac output and systemic vascular resistance
  2. 2. HypertensionHypertensionArterial BP = Cardiac Output (CO) x SystemicArterial BP = Cardiac Output (CO) x Systemicvascular resistance (SVR)vascular resistance (SVR)Cardiac OutputCardiac Output = stroke volume x beats per min= stroke volume x beats per minSystemic vascular resistanceSystemic vascular resistance = force opposing the= force opposing themovement of blood within the blood vesselsmovement of blood within the blood vesselsWhat is the effect on BP if SVR increased and COWhat is the effect on BP if SVR increased and COremains constant?remains constant?
  3. 3. HypertensionHypertensionMechanisms that Regulate BPMechanisms that Regulate BPSympathetic Nervous SystemSympathetic Nervous SystemVascular EndotheliumVascular EndotheliumRenal SystemRenal SystemEndocrine SystemEndocrine System
  4. 4. HypertensionHypertensionMechanisms that Regulate BPMechanisms that Regulate BPSympathetic Nervous System (SNS)Sympathetic Nervous System (SNS) ––norepinephrine released from sympathetic nervenorepinephrine released from sympathetic nerveendings - to receptors alpha1, alpha2, beta 1 & beta2endings - to receptors alpha1, alpha2, beta 1 & beta2Reacts within secondsReacts within secondsIncreases Heart Rate - chronotropicIncreases Heart Rate - chronotropicIncreased cardiac contractility - inotropicIncreased cardiac contractility - inotropicProduces widespread vasoconstriction inProduces widespread vasoconstriction inperipheral arteriolesperipheral arteriolesPromotes release of renin from the kidneyPromotes release of renin from the kidney
  5. 5. HypertensionHypertensionSNS Receptors Influencing B/P
  6. 6. HypertensionHypertensionMechanisms that Regulate BPMechanisms that Regulate BPSympathetic Nervous System (SNS)Sympathetic Nervous System (SNS)––Sympathetic Vasomotor Center – located in theSympathetic Vasomotor Center – located in themedulla – interacts with many areas of the brainmedulla – interacts with many areas of the brainto maintain BP within normal range underto maintain BP within normal range undervarious conditionsvarious conditionsExercise – changes to meet oxygen demandExercise – changes to meet oxygen demandPostural Changes – peripheral vasoconstrictionPostural Changes – peripheral vasoconstriction
  7. 7. HypertensionHypertensionMechanisms that Regulate BPMechanisms that Regulate BPSympathetic NervousSympathetic Nervous System (SNS)System (SNS) ––BaroreceptorsBaroreceptors: specialized nerve cells the carotid: specialized nerve cells the carotidarteries and the aortic archarteries and the aortic archSensitive to BP changes:Sensitive to BP changes:Increase: Inhibits SNSIncrease: Inhibits SNS – peripheral vessel dilation.– peripheral vessel dilation.Decreased heart rate, and decreased contractility ofDecreased heart rate, and decreased contractility ofthe heart + increased parasympathetic activity (vagusthe heart + increased parasympathetic activity (vagusnerve) decreased heart ratenerve) decreased heart rateDecrease: Activates SNSDecrease: Activates SNS – peripheral vessel– peripheral vesselconstriction, increased heart rate, and increasedconstriction, increased heart rate, and increasedcontractility of the heartcontractility of the heart
  8. 8. HypertensionHypertensionMechanisms that Regulate BPMechanisms that Regulate BPVascular EndotheliumVascular EndotheliumSingle cell layer that lines the blood vesselsSingle cell layer that lines the blood vesselsProduce vasoactive substancesProduce vasoactive substances::EDRF Endothelium-derive relaxing factorEDRF Endothelium-derive relaxing factor ––Helps maintain low arterial tone at restHelps maintain low arterial tone at restInhibits growth of the smooth muscle layerInhibits growth of the smooth muscle layerInhibits platelet aggregationInhibits platelet aggregationVasodilation – prostacyclinVasodilation – prostacyclinEndothelin (ET) potent vasoconstrictorEndothelin (ET) potent vasoconstrictorEndothelial dysfunction may contribute toEndothelial dysfunction may contribute toatherosclerosis & primary hypertensionatherosclerosis & primary hypertension
  9. 9. HypertensionHypertensionMechanisms that Regulate BPMechanisms that Regulate BPRenal SystemRenal SystemControl Na+ excretion & extracellular fluidControl Na+ excretion & extracellular fluidvolumevolumeRenal - Renin-angiotensin-aldosteroneRenal - Renin-angiotensin-aldosteroneRenin converts angiotensinogen to angiotensin IRenin converts angiotensinogen to angiotensin IAngiotensin-converting enzyme (ACE) converts I intoAngiotensin-converting enzyme (ACE) converts I intoangiotsensin IIangiotsensin IIImmediate: Vasoconstrictor – increased systemicImmediate: Vasoconstrictor – increased systemicvascular resistancevascular resistanceProlonged: Stimulates the adrenal cortex to secretProlonged: Stimulates the adrenal cortex to secretAldosterone – Na+ and Water retentionAldosterone – Na+ and Water retentionRenal MedullaRenal Medulla - Prostaglandins - vasodilator effect- Prostaglandins - vasodilator effect
  10. 10. HypertensionHypertensionRenin-AngiotensinRenin-Angiotensin
  11. 11. HypertensionHypertensionRenin-Angiotensin SystemRenin-Angiotensin System
  12. 12. HypertensionHypertensionMechanisms that Regulate BPMechanisms that Regulate BPEndocrine SystemEndocrine SystemStimulates the SNS withStimulates the SNS withEpinephrine – increases HR and contractilityEpinephrine – increases HR and contractilityActivates B2-adrenergic receptors in peripheral arterioles ofActivates B2-adrenergic receptors in peripheral arterioles ofskeletal muscle = vasodilationskeletal muscle = vasodilationActivates A1-adrenergic receptors in peripheral arterioles ofActivates A1-adrenergic receptors in peripheral arterioles ofskin and kidneys = vasoconstictionskin and kidneys = vasoconstictionAdrenal Cortex – Aldosterone – stimulates kidneys toAdrenal Cortex – Aldosterone – stimulates kidneys toretain Na+retain Na+Increased Na+ stimulates posterior pituitary – ADH –Increased Na+ stimulates posterior pituitary – ADH –reabsorbs ECF/waterreabsorbs ECF/water
  13. 13. HypertensionHypertensionAldosterone MechanismAldosterone Mechanism• Increased Aldosterone =Increased Aldosterone =• Increases sodium reabsorption =Increases sodium reabsorption =• Increases water reabsorption =Increases water reabsorption =• Increases blood volume =Increases blood volume =• Increases cardiac outputIncreases cardiac output
  14. 14. HypertensionHypertensionMechanisms that Regulate BPMechanisms that Regulate BP Regulatory mechanisms in the health person function in responseRegulatory mechanisms in the health person function in responseto the demands on the bodyto the demands on the body When Hypertension develops, one or more of these mechanismsWhen Hypertension develops, one or more of these mechanismsare defectiveare defectiveSympathetic Nervous SystemSympathetic Nervous SystemVascular EndotheliumVascular EndotheliumRenal SystemRenal SystemEndocrine SystemEndocrine System
  15. 15. Secondary HypertensionSecondary HypertensionPathophysiologyPathophysiology Specific cause of hypertension can be identifiedSpecific cause of hypertension can be identified 5+% of adult hypertension5+% of adult hypertension Causes:Causes: Coarctation or congenital narrowing of the aortaCoarctation or congenital narrowing of the aorta Renal disease – renal artery disease / parenchymalRenal disease – renal artery disease / parenchymal Endocrine disorders: Pheochromocytoma, CushingEndocrine disorders: Pheochromocytoma, CushingSyndrome, HyperaldosteronismSyndrome, Hyperaldosteronism Neurology disorders – brain tumors / head injuryNeurology disorders – brain tumors / head injury Sleep apneaSleep apnea Medications – sympathetic stimulantsMedications – sympathetic stimulants Pregnancy-induced hypertensionPregnancy-induced hypertension
  16. 16. HypertensionHypertensionPathophysiologyPathophysiologyPrimary (Essential) Hypertension:Primary (Essential) Hypertension:Elevated BP without an identified causeElevated BP without an identified causeAccounts for 95% of all cases of hypertensionAccounts for 95% of all cases of hypertensionCause – unknownCause – unknownContributing Factors:Contributing Factors: Increased SNS activity,Increased SNS activity,overproduction of Na+ retaining hormones &overproduction of Na+ retaining hormones &vasoconstrictors, increased Na+ intakevasoconstrictors, increased Na+ intakeRisk Factors:Risk Factors: ModifiableModifiable
  17. 17. Primary HypertensionPrimary HypertensionPathophysiologyPathophysiologyHeredityHeredity – interaction of genetic,– interaction of genetic,environmental, and demographic factorsenvironmental, and demographic factorsWater & Sodium RetentionWater & Sodium Retention – 20% of pts– 20% of ptswith high Na+ diet develop HTNwith high Na+ diet develop HTNAltered Renin-Angiotensin MechanismAltered Renin-Angiotensin Mechanism ––found in 20% of patientsfound in 20% of patients Stress & Increased SNS ActivityStress & Increased SNS ActivityInsulin Resistance & HyperinsulinemiaInsulin Resistance & HyperinsulinemiaEndothelial Cell DysfunctionEndothelial Cell Dysfunction
  18. 18. HypertensionHypertensionClinical ManifestationClinical ManifestationDx is made after multiple readings over several weeksDx is made after multiple readings over several weeksNIH/Joint Committee Definition:NIH/Joint Committee Definition:CategoryCategory SystolicSystolic DiastolicDiastolicOptimalOptimal <110<110 andand < 80< 80NormalNormal <120<120 andand <85<85High NormalHigh Normal 130-139130-139 oror 85-8985-89Stage 1 140-159140-159 oror 90-9990-99Stage 2Stage 2 160-179160-179 oror 100-109100-109Stage 3Stage 3 =>180=>180 oror => 110=> 110
  19. 19. Primary HypertensionPrimary HypertensionRisk FactorsRisk Factors AgeAge AlcoholAlcohol Cigarette SmokingCigarette Smoking Diabetes MellitusDiabetes Mellitus Elevated serum lipidsElevated serum lipids Excess Na+ in dietExcess Na+ in diet GenderGender Family HistoryFamily History ObesityObesity EthnicityEthnicity Sedentary LifestyleSedentary Lifestyle SocioeconomicSocioeconomic StressStress
  20. 20. Primary HypertensionPrimary HypertensionClinical ManifestationsClinical Manifestations Target Organ ComplicationsTarget Organ Complications::MyocardiumMyocardium – angina / left ventricular hypertrophy– angina / left ventricular hypertrophyBrainBrain – TIA / CVA– TIA / CVAPeripheral vascularPeripheral vascular – Peripheral pulse change– Peripheral pulse changeKidneyKidney – renal failure Creatinine / Proteinuria– renal failure Creatinine / ProteinuriaEyesEyes – Hemorrhages with or without papilledema– Hemorrhages with or without papilledema
  21. 21. Primary HypertensionPrimary HypertensionClinical ManifestationsClinical Manifestations““Silent Killer”Silent Killer” – asymptomatic and insidious– asymptomatic and insidiousSevere HTNSevere HTN – fatigue, reduced activity– fatigue, reduced activitytolerance, dyspnea, dizziness, palpitations,tolerance, dyspnea, dizziness, palpitations,anginaangina
  22. 22. HypertensionHypertensionMedical DiagnosisMedical DiagnosisHistory and Physical ExaminationHistory and Physical ExaminationRenal FunctionRenal FunctionSerum Creatinine & Urine CreatinineSerum Creatinine & Urine CreatinineClearanceClearanceElectrolytes – especially K+Electrolytes – especially K+Blood GlucoseBlood GlucoseSerum Lipids/EKGSerum Lipids/EKGAmbulatory BP MonitoringAmbulatory BP Monitoring
  23. 23. Primary HypertensionPrimary HypertensionMedical ManagementMedical ManagementRisk StratificationRisk StratificationLevel of BPLevel of BPPresence of Target Organ DiseasePresence of Target Organ DiseaseOther Risk FactorsOther Risk Factors
  24. 24. HypertensionHypertensionMedical ManagementMedical ManagementRisk StratificationRisk Stratification
  25. 25. Primary HypertensionPrimary HypertensionMedical ManagementMedical Management Lifestyle modificationLifestyle modification Nutritional therapyNutritional therapy Alcohol consumptionAlcohol consumption Physical activityPhysical activity Tobacco avoidanceTobacco avoidance Stress managementStress management Drug TherapyDrug Therapy
  26. 26. HypertensionHypertensionNutritionNutrition
  27. 27. HypertensionHypertensionRisk Factor ModificationRisk Factor Modification
  28. 28. Primary HypertensionPrimary HypertensionMedical ManagementMedical ManagementStepped ApproachStepped ApproachLifestyle modificationLifestyle modificationNot at Goal BPNot at Goal BPDrug TherapyDrug TherapyNot at Goal BPNot at Goal BPSubstitute med / add a 2nd med/ increase doseSubstitute med / add a 2nd med/ increase doseNot at Goal BPNot at Goal BPContinue adding / changing meds until controlContinue adding / changing meds until control
  29. 29. Primary HypertensionPrimary HypertensionMedical Management – Drug TherapyMedical Management – Drug Therapy DiureticsDiuretics ThiazideThiazide LoopLoop K+ SparingK+ Sparing Adrenergic Blockers/ InhibitorsAdrenergic Blockers/ Inhibitors B-Adrenergic BlockersB-Adrenergic Blockers Central Acting Adrenergic AntagonistsCentral Acting Adrenergic Antagonists Peripheral Acting Adrenergic AntagonistsPeripheral Acting Adrenergic Antagonists A-Adrenergic BlockersA-Adrenergic Blockers VasodilatorsVasodilators Angiotensin InhibitorsAngiotensin Inhibitors Calcium Channel BlockersCalcium Channel Blockers
  30. 30. HypertensionHypertensionMedication - DiureticsMedication - Diuretics
  31. 31. HypertensionHypertensionMedication – Beta-blocking AgentsMedication – Beta-blocking Agents
  32. 32. HypertensionHypertensionMedicationMedicationCalcium Channel BlockersCalcium Channel Blockers
  33. 33. HypertensionHypertensionMedicationMedicationAlpha Agonists & VasodilatorsAlpha Agonists & Vasodilators
  34. 34. HypertensionHypertensionAntihypertensive Drug TherapyAntihypertensive Drug Therapy
  35. 35. Primary HypertensionPrimary HypertensionLack of Responsiveness to TherapyLack of Responsiveness to Therapy Nonadherence to TherapyNonadherence to Therapy Drug-Related CausesDrug-Related Causes Associated conditionsAssociated conditions Secondary HypertensionSecondary Hypertension Volume overloadVolume overload
  36. 36. Primary HypertensionPrimary HypertensionHypertensive CrisisHypertensive CrisisDefinitionDefinition: Severe & abrupt elevation of BP with: Severe & abrupt elevation of BP withdiastolic > 120-130mm Hg.diastolic > 120-130mm Hg.CausesCauses::Nonadherence, renovascular changes, pre-Nonadherence, renovascular changes, pre-eclampsia, eclampsia, Pheochromocytoma,eclampsia, eclampsia, Pheochromocytoma,Rebound from abruptly stopping beta blockers,Rebound from abruptly stopping beta blockers,head injury, necrotizing vasculitis, acute aortichead injury, necrotizing vasculitis, acute aorticdissectiondissectionHypertensive Encephalopathy:Hypertensive Encephalopathy:headache, N/V, confusion, obtunded, stuporous,headache, N/V, confusion, obtunded, stuporous,seizures, blurred vision, transient blindnessseizures, blurred vision, transient blindness
  37. 37. Primary HypertensionPrimary HypertensionNursing DiagnosesNursing DiagnosesAssess:Assess: Cardiovascular status; adherence to therapy; familyCardiovascular status; adherence to therapy; familyinteraction; risk factor modification?interaction; risk factor modification?Nsg Action:Nsg Action: Supportive & reality-based; Administer meds;Supportive & reality-based; Administer meds;referrals; diagnostic preps;referrals; diagnostic preps; ask questions;ask questions;supportive care during hospitalization for acute crisissupportive care during hospitalization for acute crisisPt/Family Education:Pt/Family Education: Medications; risk factorMedications; risk factormodification; Community supportmodification; Community support
  38. 38. HypertensionHypertensionDynamics of TreatmentDynamics of Treatment
  39. 39. Primary HypertensionPrimary HypertensionCase StudyCase Study

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